Help w/ Collision -- slopes?

Hey guys. I’ve followed the Gravity tutorial here:

http://www.bit-101.com/tutorials/gravity.html

I was wondering if it’s possible to setup an object to not just bounce off the walls, but other MCs that I put on the stage??

I’ve included an example. I want the ball to be able to bounce off the ramp.
You can “throw” the ball around the screen and it will bounce around.

How can I get it to bounce off the slope without using too much CPU? Would hitTest() be too processor-intensive?